1) Field of the Invention
The present disclosure relates to a wafer leveling device which enhances flatness of a wafer during a manufacturing process and particularly flatness of a large-sized or thinned wafer which is warped and goes against precision of a manufacturing process for the wafer.
2) Description of the Prior Art
In recent years, smart phones have been a part of every consumer's life in addition to all types of wearable devices getting more popular with the general public. It can be seen from the trend of consumer goods that merchandise is being miniaturized for strengthened computing power.
Basically, the consumer goods are electronic devices characteristic of compact sizes and good computing power, both of which can be promoted with manufacturing processes based on the well-known “Moore's Law”. In semiconductor manufacturing processes, the laser marking process depends on the laser beam to label marks on wafers for the following die-saw process.
There haven been multiple patents for wafer leveling presented as follows:
Publication No. TW 1362084 discloses a device of removing warps of a wafer, comprising: a wafer support component which contacts the rim of the bottom surface of a wafer to be marked and supports the wafer; a press component placed on the wafer support component and moved between up and down positions wherein the press component at the down position applies pressure on the rim of the upper surface of the wafer, which is supported by the wafer support component, and toward the wafer support component and the press component at the up position moves upward and releases the wafer; a driving device which lifts the press component until the up position.
Publication No. TW 1233197 discloses a chip scale marker characterized in that: a laser system is used in laser marking; a wafer support on which a wafer to be marked is carried comprises a vacuum panel centrally mounted on the wafer support to absorb the wafer and a wafer spin unit installed around the vacuum panel and being opposite to an open region of the laser system; a camera over the wafer support takes photos of the wafer; a warp removal unit over the wafer support eliminates any warp of the wafer.
Publication No. TW 1487017 discloses a lamination device comprising an upper gripper and a lower gripper to hold a wafer: the upper gripper which resists a certain pressure is warped at the central portion; the lower gripper is downward provided with a peripheral insulating ring supporting the lower gripper. The insulating ring comprises a plurality of insulating components; the insulating ring is supported with a plurality of supporting components which form a supporting ring. Each of the supporting components is fixed on the lower gripper with a corresponding screw. A screw is driven into an insulating component and a through hole opened to support the insulating component. A through hole is greater than a screw in diameter.
However, pressures are applied on front and back rims of a warped wafer during calibrations by two planes at which there is no flexible space but bring more stresses on the wafer.
To settle the above issues, the present disclosure is to offer a wafer leveling device.